/*****************************************************************************
 * audio.c: transcoding stream output module (audio)
 *****************************************************************************
 * Copyright (C) 2003-2009 VLC authors and VideoLAN
 * $Id$
 *
 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
 *          Gildas Bazin <gbazin@videolan.org>
 *          Jean-Paul Saman <jpsaman #_at_# m2x dot nl>
 *          Antoine Cellerier <dionoea at videolan dot org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/

#include "transcode.h"

#include <vlc_aout.h>
#include <vlc_input.h>
#include <vlc_meta.h>
#include <vlc_modules.h>

static const int pi_channels_maps[9] =
{
    0,
    AOUT_CHAN_CENTER,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
    AOUT_CHAN_LFE  | AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARLEFT
     | AOUT_CHAN_REARRIGHT,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
     | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
     | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
     | AOUT_CHAN_REARCENTER | AOUT_CHAN_MIDDLELEFT
     | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT
     | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT
     | AOUT_CHAN_LFE,
};

static int audio_update_format( decoder_t *p_dec )
{
    sout_stream_id_sys_t *id     = p_dec->p_queue_ctx;

    p_dec->fmt_out.audio.i_format = p_dec->fmt_out.i_codec;
    aout_FormatPrepare( &p_dec->fmt_out.audio );

    vlc_mutex_lock(&id->fifo.lock);
    id->audio_dec_out = p_dec->fmt_out.audio;
    vlc_mutex_unlock(&id->fifo.lock);

    return ( p_dec->fmt_out.audio.i_bitspersample > 0 ) ? 0 : -1;
}

static int transcode_audio_initialize_filters( sout_stream_t *p_stream, sout_stream_id_sys_t *id,
                                               sout_stream_sys_t *p_sys )
{
    /* Load user specified audio filters */
    /* XXX: These variable names come kinda out of nowhere... */
    var_Create( p_stream, "audio-time-stretch", VLC_VAR_BOOL );
    var_Create( p_stream, "audio-filter", VLC_VAR_STRING );
    if( p_sys->psz_af )
        var_SetString( p_stream, "audio-filter", p_sys->psz_af );
    id->p_af_chain = aout_FiltersNew( p_stream, &id->audio_dec_out,
                                      &id->p_encoder->fmt_in.audio, NULL, NULL );
    var_Destroy( p_stream, "audio-filter" );
    var_Destroy( p_stream, "audio-time-stretch" );
    if( id->p_af_chain == NULL )
    {
        msg_Err( p_stream, "Unable to initialize audio filters" );
        module_unneed( id->p_encoder, id->p_encoder->p_module );
        id->p_encoder->p_module = NULL;
        module_unneed( id->p_decoder, id->p_decoder->p_module );
        id->p_decoder->p_module = NULL;
        return VLC_EGENERIC;
    }
    id->fmt_audio.i_rate = id->audio_dec_out.i_rate;
    id->fmt_audio.i_physical_channels = id->audio_dec_out.i_physical_channels;
    return VLC_SUCCESS;
}

static int transcode_audio_initialize_encoder( sout_stream_id_sys_t *id, sout_stream_t *p_stream )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;

    /* Complete destination format */
    id->p_encoder->fmt_out.i_codec = p_sys->i_acodec;
    id->p_encoder->fmt_out.audio.i_rate = p_sys->i_sample_rate > 0 ?
        p_sys->i_sample_rate : id->audio_dec_out.i_rate;
    id->p_encoder->fmt_out.i_bitrate = p_sys->i_abitrate;
    id->p_encoder->fmt_out.audio.i_bitspersample = id->audio_dec_out.i_bitspersample;
    id->p_encoder->fmt_out.audio.i_channels = p_sys->i_channels > 0 ?
        p_sys->i_channels : id->audio_dec_out.i_channels;
    assert(id->p_encoder->fmt_out.audio.i_channels > 0);
    if( id->p_encoder->fmt_out.audio.i_channels >= ARRAY_SIZE(pi_channels_maps) )
        id->p_encoder->fmt_out.audio.i_channels = ARRAY_SIZE(pi_channels_maps) - 1;

    id->p_encoder->fmt_in.audio.i_physical_channels =
    id->p_encoder->fmt_out.audio.i_physical_channels =
        pi_channels_maps[id->p_encoder->fmt_out.audio.i_channels];

    /* Initialization of encoder format structures */
    es_format_Init( &id->p_encoder->fmt_in, id->p_decoder->fmt_in.i_cat,
                    id->audio_dec_out.i_format );
    id->p_encoder->fmt_in.audio.i_format = id->audio_dec_out.i_format;
    id->p_encoder->fmt_in.audio.i_rate = id->p_encoder->fmt_out.audio.i_rate;
    id->p_encoder->fmt_in.audio.i_physical_channels =
        id->p_encoder->fmt_out.audio.i_physical_channels;
    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );

    id->p_encoder->p_cfg = p_stream->p_sys->p_audio_cfg;
    id->p_encoder->p_module =
        module_need( id->p_encoder, "encoder", p_sys->psz_aenc, true );
    /* p_sys->i_acodec = 0 if there isn't acodec defined */
    if( !id->p_encoder->p_module && p_sys->i_acodec )
    {
        msg_Err( p_stream, "cannot find audio encoder (module:%s fourcc:%4.4s). "
                           "Take a look few lines earlier to see possible reason.",
                 p_sys->psz_aenc ? p_sys->psz_aenc : "any",
                 (char *)&p_sys->i_acodec );
        module_unneed( id->p_decoder, id->p_decoder->p_module );
        id->p_decoder->p_module = NULL;
        return VLC_EGENERIC;
    }

    id->p_encoder->fmt_out.i_codec =
        vlc_fourcc_GetCodec( AUDIO_ES, id->p_encoder->fmt_out.i_codec );

    /* Fix input format */
    id->p_encoder->fmt_in.audio.i_format = id->p_encoder->fmt_in.i_codec;
    if( !id->p_encoder->fmt_in.audio.i_physical_channels )
    {
        if( id->p_encoder->fmt_in.audio.i_channels < (sizeof(pi_channels_maps) / sizeof(*pi_channels_maps)) )
            id->p_encoder->fmt_in.audio.i_physical_channels =
                      pi_channels_maps[id->p_encoder->fmt_in.audio.i_channels];
    }
    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );

    return VLC_SUCCESS;
}

static int decoder_queue_audio( decoder_t *p_dec, block_t *p_audio )
{
    sout_stream_id_sys_t *id = p_dec->p_queue_ctx;

    vlc_mutex_lock(&id->fifo.lock);
    *id->fifo.audio.last = p_audio;
    id->fifo.audio.last = &p_audio->p_next;
    vlc_mutex_unlock(&id->fifo.lock);
    return 0;
}

static block_t *transcode_dequeue_all_audios( sout_stream_id_sys_t *id )
{
    vlc_mutex_lock(&id->fifo.lock);
    block_t *p_audio_bufs = id->fifo.audio.first;
    id->fifo.audio.first = NULL;
    id->fifo.audio.last = &id->fifo.audio.first;
    vlc_mutex_unlock(&id->fifo.lock);

    return p_audio_bufs;
}

static int transcode_audio_new( sout_stream_t *p_stream,
                                sout_stream_id_sys_t *id )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;

    /*
     * Open decoder
     */

    /* Initialization of decoder structures */
    id->p_decoder->pf_decode = NULL;
    id->p_decoder->pf_queue_audio = decoder_queue_audio;
    id->p_decoder->p_queue_ctx = id;
    id->p_decoder->pf_aout_format_update = audio_update_format;
    /* id->p_decoder->p_cfg = p_sys->p_audio_cfg; */
    id->p_decoder->p_module =
        module_need( id->p_decoder, "audio decoder", "$codec", false );
    if( !id->p_decoder->p_module )
    {
        msg_Err( p_stream, "cannot find audio decoder" );
        return VLC_EGENERIC;
    }

    vlc_mutex_lock(&id->fifo.lock);
    /* The decoder fmt_out can be uninitialized here (since it can initialized
     * asynchronously). Fix audio_dec_out with default values in that case.
     * This should be enough to initialize the encoder for the first time (it
     * will be reloaded when all information from the decoder are available).
     * */
    id->audio_dec_out = id->p_decoder->fmt_out.audio;
    id->audio_dec_out.i_format = id->p_decoder->fmt_out.i_codec;
    if (id->audio_dec_out.i_format == 0)
        id->audio_dec_out.i_format = VLC_CODEC_FL32;
    if (id->audio_dec_out.i_rate == 0)
    {
        id->audio_dec_out.i_rate = id->p_decoder->fmt_in.audio.i_rate;
        if (id->audio_dec_out.i_rate == 0)
            id->audio_dec_out.i_rate = 48000;
    }
    if (id->audio_dec_out.i_physical_channels == 0)
    {
        id->audio_dec_out.i_physical_channels = id->p_decoder->fmt_in.audio.i_physical_channels;
        if (id->audio_dec_out.i_physical_channels == 0)
            id->audio_dec_out.i_physical_channels = AOUT_CHANS_STEREO;
    }
    aout_FormatPrepare( &id->audio_dec_out );

    /*
     * Open encoder
     */
    if( transcode_audio_initialize_encoder( id, p_stream ) == VLC_EGENERIC )
    {
        vlc_mutex_unlock(&id->fifo.lock);
        return VLC_EGENERIC;
    }

    if( unlikely( transcode_audio_initialize_filters( p_stream, id, p_sys ) != VLC_SUCCESS ) )
    {
        vlc_mutex_unlock(&id->fifo.lock);
        return VLC_EGENERIC;
    }
    vlc_mutex_unlock(&id->fifo.lock);

    return VLC_SUCCESS;
}

void transcode_audio_close( sout_stream_id_sys_t *id )
{
    /* Close decoder */
    if( id->p_decoder->p_module )
        module_unneed( id->p_decoder, id->p_decoder->p_module );
    id->p_decoder->p_module = NULL;

    if( id->p_decoder->p_description )
        vlc_meta_Delete( id->p_decoder->p_description );
    id->p_decoder->p_description = NULL;

    /* Close encoder */
    if( id->p_encoder->p_module )
        module_unneed( id->p_encoder, id->p_encoder->p_module );
    id->p_encoder->p_module = NULL;

    /* Close filters */
    if( id->p_af_chain != NULL )
        aout_FiltersDelete( (vlc_object_t *)NULL, id->p_af_chain );
}

int transcode_audio_process( sout_stream_t *p_stream,
                                    sout_stream_id_sys_t *id,
                                    block_t *in, block_t **out )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;
    *out = NULL;

    int ret = id->p_decoder->pf_decode( id->p_decoder, in );
    if( ret != VLCDEC_SUCCESS )
        return VLC_EGENERIC;

    block_t *p_audio_bufs = transcode_dequeue_all_audios( id );
    if( p_audio_bufs == NULL )
        goto end;

    do
    {
        block_t *p_audio_buf = p_audio_bufs;
        p_audio_bufs = p_audio_bufs->p_next;
        p_audio_buf->p_next = NULL;

        if( id->b_error )
        {
            block_Release( p_audio_buf );
            continue;
        }

        vlc_mutex_lock(&id->fifo.lock);
        if( unlikely( !id->p_encoder->p_module ) )
        {
            if( transcode_audio_initialize_encoder( id, p_stream ) )
            {
                msg_Err( p_stream, "cannot create audio chain" );
                vlc_mutex_unlock(&id->fifo.lock);
                goto error;
            }
            if( unlikely( transcode_audio_initialize_filters( p_stream, id, p_sys ) != VLC_SUCCESS ) )
            {
                vlc_mutex_unlock(&id->fifo.lock);
                goto error;
            }
            date_Init( &id->next_input_pts, id->audio_dec_out.i_rate, 1 );
            date_Set( &id->next_input_pts, p_audio_buf->i_pts );

            if (!id->id)
            {
                id->id = sout_StreamIdAdd( p_stream->p_next, &id->p_encoder->fmt_out );
                if (!id->id)
                {
                    vlc_mutex_unlock(&id->fifo.lock);
                    goto error;
                }
            }
        }

        /* Check if audio format has changed, and filters need reinit */
        if( unlikely( ( id->audio_dec_out.i_rate != id->fmt_audio.i_rate ) ||
                      ( id->audio_dec_out.i_physical_channels != id->fmt_audio.i_physical_channels ) ) )
        {
            msg_Info( p_stream, "Audio changed, trying to reinitialize filters" );
            if( id->p_af_chain != NULL )
                aout_FiltersDelete( (vlc_object_t *)NULL, id->p_af_chain );

            if( transcode_audio_initialize_filters( p_stream, id, p_sys ) != VLC_SUCCESS )
            {
                vlc_mutex_unlock(&id->fifo.lock);
                goto error;
            }

            /* Set next_input_pts to run with new samplerate */
            date_Init( &id->next_input_pts, id->fmt_audio.i_rate, 1 );
            date_Set( &id->next_input_pts, p_audio_buf->i_pts );
        }
        vlc_mutex_unlock(&id->fifo.lock);

        if( p_sys->b_master_sync )
        {
            vlc_tick_t i_pts = date_Get( &id->next_input_pts );
            vlc_tick_t i_drift = 0;

            if( likely( p_audio_buf->i_pts != VLC_TICK_INVALID ) )
                i_drift = p_audio_buf->i_pts - i_pts;

            if ( unlikely(i_drift > MASTER_SYNC_MAX_DRIFT
                 || i_drift < -MASTER_SYNC_MAX_DRIFT) )
            {
                msg_Dbg( p_stream,
                    "audio drift is too high (%"PRId64"), resetting master sync",
                    i_drift );
                date_Set( &id->next_input_pts, p_audio_buf->i_pts );
                i_pts = date_Get( &id->next_input_pts );
                if( likely(p_audio_buf->i_pts != VLC_TICK_INVALID ) )
                    i_drift = p_audio_buf->i_pts - i_pts;
            }
            p_sys->i_master_drift = i_drift;
            date_Increment( &id->next_input_pts, p_audio_buf->i_nb_samples );
        }

        p_audio_buf->i_dts = p_audio_buf->i_pts;

        /* Run filter chain */
        p_audio_buf = aout_FiltersPlay( id->p_af_chain, p_audio_buf,
                                        INPUT_RATE_DEFAULT );
        if( !p_audio_buf )
            goto error;

        p_audio_buf->i_dts = p_audio_buf->i_pts;

        block_t *p_block = id->p_encoder->pf_encode_audio( id->p_encoder, p_audio_buf );

        block_ChainAppend( out, p_block );
        block_Release( p_audio_buf );
        continue;
error:
        if( p_audio_buf )
            block_Release( p_audio_buf );
        id->b_error = true;
    } while( p_audio_bufs );

end:
    /* Drain encoder */
    if( unlikely( !id->b_error && in == NULL ) )
    {
        if( id->p_encoder->p_module )
        {
            block_t *p_block;
            do {
               p_block = id->p_encoder->pf_encode_audio(id->p_encoder, NULL );
               block_ChainAppend( out, p_block );
            } while( p_block );
        }
    }

    return id->b_error ? VLC_EGENERIC : VLC_SUCCESS;
}

bool transcode_audio_add( sout_stream_t *p_stream, const es_format_t *p_fmt,
            sout_stream_id_sys_t *id )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;

    msg_Dbg( p_stream,
             "creating audio transcoding from fcc=`%4.4s' to fcc=`%4.4s'",
             (char*)&p_fmt->i_codec, (char*)&p_sys->i_acodec );

    id->fifo.audio.first = NULL;
    id->fifo.audio.last = &id->fifo.audio.first;

    /* Complete destination format */
    id->p_encoder->fmt_out.i_codec = p_sys->i_acodec;
    id->p_encoder->fmt_out.audio.i_rate = p_sys->i_sample_rate > 0 ?
        p_sys->i_sample_rate : p_fmt->audio.i_rate;
    id->p_encoder->fmt_out.i_bitrate = p_sys->i_abitrate;
    id->p_encoder->fmt_out.audio.i_bitspersample =
        p_fmt->audio.i_bitspersample;
    id->p_encoder->fmt_out.audio.i_channels = p_sys->i_channels > 0 ?
        p_sys->i_channels : p_fmt->audio.i_channels;

    if( id->p_encoder->fmt_out.audio.i_channels >= ARRAY_SIZE(pi_channels_maps) )
        id->p_encoder->fmt_out.audio.i_channels = ARRAY_SIZE(pi_channels_maps) - 1;

    id->p_encoder->fmt_in.audio.i_physical_channels =
    id->p_encoder->fmt_out.audio.i_physical_channels =
            pi_channels_maps[id->p_encoder->fmt_out.audio.i_channels];

    /* Build decoder -> filter -> encoder chain */
    if( transcode_audio_new( p_stream, id ) == VLC_EGENERIC )
    {
        msg_Err( p_stream, "cannot create audio chain" );
        return false;
    }

    /* Open output stream */
    id->b_transcode = true;

    /* Reinit encoder again later on, when all information from decoders
     * is available. */
    if( id->p_encoder->p_module )
    {
        module_unneed( id->p_encoder, id->p_encoder->p_module );
        id->p_encoder->p_module = NULL;
        if( id->p_encoder->fmt_out.p_extra )
        {
            free( id->p_encoder->fmt_out.p_extra );
            id->p_encoder->fmt_out.p_extra = NULL;
            id->p_encoder->fmt_out.i_extra = 0;
        }
        if( id->p_af_chain != NULL )
            aout_FiltersDelete( (vlc_object_t *)NULL, id->p_af_chain );
        id->p_af_chain = NULL;
    }
    return true;
}